U.S. patent application number 12/482302 was filed with the patent office on 2009-12-17 for optical connector stop ring, optical fiber cord with optical connector using the same and method for manufacturing optical fiber cord with optical connector.
This patent application is currently assigned to Seikoh Giken Co., Ltd.. Invention is credited to Norimasa Arai, Yasunari Kawasaki, Junji Taira.
Application Number | 20090310919 12/482302 |
Document ID | / |
Family ID | 41414879 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090310919 |
Kind Code |
A1 |
Arai; Norimasa ; et
al. |
December 17, 2009 |
OPTICAL CONNECTOR STOP RING, OPTICAL FIBER CORD WITH OPTICAL
CONNECTOR USING THE SAME AND METHOD FOR MANUFACTURING OPTICAL FIBER
CORD WITH OPTICAL CONNECTOR
Abstract
To provide an optical fiber cord with an optical connector of
higher flexibility resistance, and the method for manufacturing the
same are disclosed. An optical fiber cord with an optical
connector, wherein said fiber cord, wherein said the optical
connector comprising a stop ring having a through hole formed
therein, though which said optical fiber is disposed; a crimping
ring being disposed around said optical fiber to crimp said stop
ring and said optical fiber cord; a ferrule being disposed at the
tip end part of said optical fiber in said optical fiber cord; a
spring being disposed around said optical fiber and between said
ferrule and said stop ring; a plug frame being engaged with said
stop ring; a grip being engaged with said plug frame; wherein said
through hole of said stop ring having a stepwisely narrowing part
in which a hole diameter is gradually reduced from said crimping
part side to said ferrule side.
Inventors: |
Arai; Norimasa; (Chiba,
JP) ; Taira; Junji; (Chiba, JP) ; Kawasaki;
Yasunari; (Chiba, JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
Seikoh Giken Co., Ltd.
Chiba
JP
|
Family ID: |
41414879 |
Appl. No.: |
12/482302 |
Filed: |
June 10, 2009 |
Current U.S.
Class: |
385/87 ;
264/1.25 |
Current CPC
Class: |
G02B 6/3887
20130101 |
Class at
Publication: |
385/87 ;
264/1.25 |
International
Class: |
G02B 6/36 20060101
G02B006/36; B29D 11/00 20060101 B29D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 12, 2008 |
JP |
2008-154749 |
Apr 15, 2009 |
JP |
2009-098673 |
Claims
1. An optical fiber cord with an optical connector, wherein said
optical fiber cord comprising: an optical fiber coated with buffer
member; a tension member disposed around said optical fiber; and an
outer jacket accommodating said optical fiber and said tension
member therein; and wherein said optical connector comprising: a
stop ring having a through hole formed therein having a crimping
part at one end thereof, though which said optical fiber is
disposed; a crimping ring being disposed around said optical fiber
to crimp said stop ring and said optical fiber cord; a ferrule
being disposed at the tip end part of said optical fiber in said
optical fiber cord; a spring being disposed around said optical
fiber and between said ferrule and said stop ring; a plug frame
being engaged with said stop ring; and a grip being engaged with
said plug frame; wherein said through hole of said stop ring having
a stepwisely narrowing part in which a hole diameter is gradually
reduced from said crimping part side to said ferrule side.
2. The optical fiber cord with the optical connector according to
claim 1, in which said diameter of said through hole at said
crimping part side in said stop ring is larger than the outer
diameter of said optical fiber cord.
3. The optical fiber cord with the optical connector according to
claim 2, in which said stepwisely narrowing part is located at a
position from 10 mm to 30 mm apart from the end surface of said
crimping part side.
4. A stop ring for an optical connector having a through hole
formed therein and a stepwisely narrowing part in which a hole
diameter is gradually reduced from a crimping part side to a
ferrule side.
5. A method for fixing an optical fiber to a ferrule, comprising
the steps of: passing an optical fiber cord through a crimping
ring; exposing said optical fiber from the optical fiber cord;
inserting said optical fiber cord in which said optical fiber is
exposed into a stop ring having a through hole formed thereto and a
stepwisely narrowing part in which a hole diameter is gradually
reduced from a crimping part side to a ferrule side formed thereto,
from the crimping part side; passing said optical fiber through a
spring; and fixing a ferrule to the tip end of said optical
fiber.
6. A method for manufacturing an optical fiber cord with an optical
connector, comprising the steps of: passing an optical fiber cord
through a boot and a crimping ring; exposing an optical fiber from
the optical fiber cord; inserting said optical fiber cord from the
crimping part side, in which said optical fiber is exposed into a
stop ring having a through hole formed thereto and a stepwisely
narrowing part, in which a hole diameter is gradually reduced from
the crimping part side to the ferrule side; passing the optical
fiber through a spring; fixing a ferrule to the tip end of the
optical fiber; sliding said optical fiber cord from said stop ring
to engage a plug frame, said ferrule, and said stop ring with one
another; and engaging said plug frame with a grip part.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of
Japanese Patent Application No. 2008-154749, filed on Jun. 12,
2008, in the Japan Patent Office, and Japanese Patent Application
No. 2009-098673, filed on Apr. 15, 2009, in the Japan Patent
Office. The disclosures of the foregoing applications are
incorporated herein in their entireties by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an optical connector stop
ring, an optical fiber cord with an optical connector using the
same, and methods for manufacturing an optical fiber cord with an
optical connector.
[0004] 2. Description of the Related Art
[0005] In recent years, optical communication systems using optical
fibers have been actively developed with increasing speed and
capacity of information communication. In such optical
communication systems, optical communication is generally performed
by connecting an optical connector with the tip end of an optical
fiber cord that holds optical fiber the inside thereof, and
connecting this optical connector with a device such as an optical
communication module.
[0006] In general, the optical fiber connector may be formed by
passing optical fiber through a boot, a crimping ring, a stop ring
and a spring, exposing the optical fiber of the fiber cord, fixing
a ferrule to the tip end of the exposed optical fiber, adjusting
the locations of said members above for the optical fiber cord,
engaging a plug frame with the stop ring, crimping the stop ring
and the optical fiber cord by the crimping ring, attaching the
boot, and finally engaging a grip with the plug frame.
SUMMARY OF THE INVENTION
[0007] However, there is a problem of lower flex resistance where
the outer jacket of the optical fiber cord is cut to take out the
tension member from the inside thereof, the fiber cord is forced to
make narrow to pass through the stop ring, and the optical fiber is
fixed to the ferrule, as compared with the case in which the outer
jacket is not cut to split. Moreover, in the addition to the above
problem, there is a possibility of invasion of foreign substances
and moisture, or ruin the appearance when the outer jacket is
subjected to cut to split. Therefore, it is difficult to employ a
boot having a part where the optical fiber cord is exposed, and
there is a problem of that it cannot be avoid utilizing the boot of
low flexibility.
[0008] Accordingly, there is a need for an optical fiber cord
exhibiting higher flexibility resistance with an optical connector,
and methods for manufacturing the same.
[0009] In one embodiment, an optical fiber cord can be inserted
into a stop ring, and a length of the optical fiber can be secured
enough to fix with the ferrule without cutting the outer jacket, by
configuring the stop ring with a through-hole in which the diameter
at the crimping part side is larger than the diameter at the
ferrule end surface side. As a result, in some embodiments, an
optical fiber cord having high flexibility resistance can be formed
with an optical connector without sacrificing its bending
property.
[0010] In another embodiment, the optical fiber cord with an
optical connector according to one aspect of the present invention
comprises optical fiber having a buffer member formed, a tension
member disposed around the optical fiber, and an outer jacket for
containing the optical fiber and the tension member, in which
optical connector includes a stop ring having a through-hole formed
thereto and a crimping part at one end and containing the optical
fiber disposed within the through-hole, a crimping ring for
crimping the stop ring and the optical fiber cord, a ferrule
disposed at the tip end part of the optical fiber of the optical
fiber cord, a spring disposed between the ferrule and the stop
ring, a plug frame to be engaged with the stop ring, and a grip
part to be engaged with the plug frame, wherein the through-hole of
the stop ring having a stepwisely narrowing part where a diameter
is gradually reduced from the crimping part side to the ferrule
side.
[0011] In yet another embodiment, a stop ring for an optical
connector has a through-hole formed thereto and a stepwisely
narrowing part where a diameter is gradually reduced from the
crimping part side to the ferrule side.
[0012] In yet another embodiment, a method for fixing ferrule to an
optical fiber comprises the steps of: passing an optical fiber cord
through a crimping ring; exposing optical fiber from the optical
fiber cord; inserting the optical fiber cord in which the optical
fiber is exposed, into a stop ring, the stop ring having a through
hole formed thereto and a stepwisely narrowing part in which a
diameter of the through hole is gradually reduced from a crimping
part side to a ferrule side, from the crimping part side; passing
the optical fiber through a spring; and fixing a ferrule to the tip
end of the optical fiber.
[0013] In other embodiments, methods for manufacturing the optical
fiber cord with the optical fiber connector comprise the steps of:
passing an optical fiber cord through a boot and a crimping ring;
exposing optical fiber from the optical fiber cord; inserting the
optical fiber cord from the crimping part side, in which the
optical fiber is exposed into a stop ring, the stop ring having a
through hole from the crimping part side and a stepwisely narrowing
part in which a diameter of the through hole is gradually reduced
from the crimping part side to the ferrule side thereof, from the
crimping part side; passing the optical fiber through a spring;
fixing a ferrule to the tip end of the optical fiber; sliding the
optical fiber cord from the stop ring to engage the plug frame, a
ferrule, and a stop ring with one another; and engaging the plug
frame with a grip part.
[0014] Therefore, in some embodiments, optical fiber cord with an
optical connector of high flexibility resistance, and methods for
manufacturing the same can be provided.
[0015] For purposes of summarizing the invention and the advantages
achieved over the prior art, certain objects and advantages of the
invention have been described above and as further described below.
Of course, it is to be understood that not necessarily all such
objects or advantages may be achieved in accordance with any
particular embodiment of the invention. Thus, for example, those
skilled in the art will recognize that the invention may be
embodied or carried out in a manner that achieves or optimizes one
advantage or group of advantages as taught herein without
necessarily achieving other objects or advantages as may be taught
or suggested herein.
[0016] All of these embodiments are intended to be within the scope
of the invention herein disclosed. These and other embodiments of
the present invention will become readily apparent to those skilled
in the art from the following detailed description of the preferred
embodiments having reference to the attached figures, the invention
not being limited to any particular preferred embodiment(s)
disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other aspects of the invention will be readily
apparent from the following description and from the appended
drawings (not to scale), which are meant to illustrate and not to
limit the invention, and in which:
[0018] FIG. 1 shows a schematic perspective view (A), a plan view
(B), and a cross sectional view (C) illustrating an optical fiber
cord with an optical connector of one embodiment according to the
present invention.
[0019] FIG. 2 shows a perspective view (A), a plan view (B), and a
cross sectional view (C) illustrating a stop ring for an optical
connector of one embodiment according to the present invention.
[0020] FIG. 3 shows a cross sectional view illustrating near the
stepwisely narrowing part in the stop ring of one embodiment
according to the present invention.
[0021] FIG. 4 shows a plan view (A) and a cross sectional view (B)
illustrating a crimping ring of one embodiment according to the
present invention.
[0022] FIG. 5 shows a plan view (A) and a cross sectional view (B)
illustrating a ferrule of one embodiment according to the present
invention.
[0023] FIG. 6 shows a cross sectional view illustrating a spring of
one embodiment according to the present invention.
[0024] FIG. 7(A) shows a schematic plan view and a schematic cross
sectional view illustrating a boot in which parts for exposing an
optical fiber cord are formed.
[0025] FIG. 7(B) shows a schematic plan view and a schematic cross
sectional view illustrating a boot in which no part for exposing
the optical fiber cord is formed.
[0026] FIG. 8 shows a method for manufacturing an optical fiber
cord with an optical fiber connector of one embodiment according to
the present invention.
[0027] FIG. 9 illustrates a step of passing an optical fiber cord
through a boot and a crimping ring.
[0028] FIG. 10 illustrates a step of exposing an optical fiber from
an optical fiber cord.
[0029] FIG. 11 illustrates a step of inserting an optical fiber
cord from a crimping part side into a stop ring.
[0030] FIG. 12 illustrates a step of passing an optical fiber
through a spring.
[0031] FIG. 13 illustrates a step of fixing a ferrule to a tip end
of an optical fiber.
[0032] FIG. 14 illustrates a plan view (A) and a cross sectional
view (B) of the step of sliding an optical fiber cord from a stop
ring to engage a plug frame and the like with one another, and a
plan view (C) after the plug frame is engaged with the stop
ring.
[0033] FIG. 15 is a explanatory diagram illustrating a method for
crimping a stop ring with a crimping ring.
EXPLANATION OF NUMERICAL REFERENCES
[0034] 1: optical fiber cord; [0035] 1d: outer diameter (of the
optical fiber cord); [0036] 2: optical connector; [0037] 11:
buffered optical fiber; [0038] 12: buffer member; [0039] 13:
tension member; [0040] 14: outer jacket; [0041] 15: optical fiber;
[0042] 21: stop ring; [0043] 22: crimping ring; [0044] 23: ferrule;
[0045] 24: spring; [0046] 24d: inner diameter (of the spring);
[0047] 25: plug frame; [0048] 26: grip; [0049] 27: boot; [0050]
211: through hole; [0051] 212: crimping part; [0052] 212d: hole
diameter (at the crimping part side); [0053] 213: ferrule side
part; [0054] 214: stepwisely narrowing part; [0055] 221: through
hole (of the sealing ring) [0056] 231: flange part; and [0057] 232:
cylindrical part.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0058] The embodiments according to the present invention will now
be explained in detail with reference to the drawings, but the
present invention is not intended to limited to these embodiments
and many different embodiments can be implemented.
[0059] In certain optical fiber cords, optical fiber cords having
an average diameter of about 3 mm or less are generally used,
although the use of optical fiber cord having a larger average
diameter of about 4 mm or about 5 mm for house wiring has been
considered.
[0060] However, a conventional stop ring used for the optical
connector has a narrow diameter of its through hole which, as it
is, is not capable of passing through the optical fiber cord of the
large diameter as mentioned above. Therefore, the optical fiber
must be exposed for the entire length of the stop ring, and the
ferrule must be fixed with the stop ring while its location is
unstable, which causes difficulty in fixing the ferrule with the
optical fiber.
[0061] To overcome these difficulties, the casing of the optical
fiber cord is cut open to take out a tension member to be disposed
inside thereof to temporarily force to make the diameter of the
optical fiber cord narrower and the stop ring is passed through the
cord to fix the optical fiber to the ferrule.
[0062] In some embodiments, an optical fiber cord with an optical
connector is provided. The optical fiber cord may include optical
fiber with a buffer member formed thereto; a tension member
disposed around said optical fiber; and an outer jacket. The
optical connector may include: a stop ring having a through hole
formed therein having a crimping part at one end thereof, though
which said optical fiber are disposed; a crimping ring being
disposed around said optical fiber to crimp said stop ring and said
optical fiber cord; a ferrule being disposed at the tip end part of
said optical fiber in said optical fiber cord; a spring being
disposed around said optical fiber and between said ferrule and
said stop ring; a plug frame being engaged with said stop ring; and
a grip being engaged with said plug frame; wherein said through
hole of said stop ring having a stepwisely narrowing part in which
a hole diameter is gradually reduced from said crimping part side
to said ferrule side.
[0063] FIG. 1 shows a schematic perspective view (FIG. 1(A)), a
plan view (FIG. 1(B)), and a schematic cross sectional view (FIG.
1(C)) of an optical fiber cord with an optical connector of one
embodiment. In some embodiments, to one end of an optical fiber
cord 1, an optical connector 2 can be provided, in which the
optical fiber cord 1 can comprise buffered optical fiber 11 having
optical fiber 15 with a buffer member 12 formed thereto, a tension
member 13 disposed around the buffered optical fiber 11, and an
outer jacket 14 for containing the buffered optical fiber 11 and
the tension member 13. Further, the optical connector 2 comprises a
stop ring 21 for disposing the buffered optical member 11 into a
through hole 211 formed thereto, a crimping ring 22 for crimping
the stop ring 21 and the optical fiber cord 1, a ferrule 23
disposed at the tip end part of an optical fiber 15 in the optical
fiber cord 1, a spring 24 disposed between the ferrule 23 and the
stop ring 21, a plug frame 25 to be engaged with the stop ring 21,
a grip 26 to be engaged with the plug frame 25, and a boot for
attaching a part of the stop ring 21, the crimping ring 22, and a
part of the optical fiber cord 1, in which the through hole 211
having a stepwisely narrowing part 214 where a diameter is
gradually reduced from the crimping part side 212 to the ferrule
side 213.
[0064] In one embodiment, an optical fiber 15 may include a core
and a clad being disposed around the core and having a lower index
of refraction than that of the core, thereby efficiently
transmitting light. For materials of the core and the clad of the
optical fiber, though any known materials as far as they have light
transmission ability and appropriate index of refraction can be
employed without any limitation, for example, glasses, plastics and
the like are suitable. Moreover, a circular shape is preferred for
the cross sections of the optical fiber 15.
[0065] In some embodiments, the buffer member 12 may be disposed
around the optical fiber 15, and used to protect the optical fiber
15. For materials of the buffer member 12, for example, silicone
resins, nylon resins, elastomers, UV curable resins, and the like
can suitably be employed, but not limited thereto.
[0066] In some embodiments, the tension member 13 can relieve the
tensile strength in the case where the tensile strength is
generated, for example, by bending the buffered optical fiber 11
coated with the buffer member 12 to prevent the optical fiber 15
being damaged. Although, materials of the tension member 13 are not
limited as far as the materials have the above functions, for
example, aramid fibers and the like are suitable.
[0067] In one embodiment, the outer jacket 14 may contain and
protect the buffered optical fiber 11 coated by the buffer member
12 and the tension member 13. Although, vinyl chloride resins,
elastomers and the like are suitable for materials for the outer
jacket 14, but not limited thereto. Further, though the diameter of
the outer jacket is not limited, it is preferable that the outer
jacket has an outer diameter 1d which is larger than the inner
diameter of 24d of the spring to be disposed, being described
below, for example, preferably, about 3.5 mm or larger, more
preferably, about 4 mm to about 5 mm, since the optical connector
of the embodiment has a large diameter, thereby exhibiting
extremely high effects when the conventional optical fiber cord as
it is cannot be passed through the stop ring 21.
[0068] Now, FIG. 2 shows a perspective view (FIG. 2(A)), a plan
view (FIG. 2(B)), and a cross sectional view (FIG. 2(C)) of the
stop ring 21 of an embodiment. As shown in the figure, a through
hole 211 is formed to the stop ring 21 in the optical connector 2
of the embodiment, and this through hole 211 has a stepwisely
narrowing part 214 where a diameter is gradually reduced from the
crimping part side 212 to the ferrule side 213. Moreover, it is
necessary that the hole-diameter 212d of the crimping part side 212
is larger than the outer diameter 1d of the optical fiber cord 1 to
be inserted (see, FIG. 1). In this way, though it would be clearly
understood from the following steps, the optical fiber cord 1 is
inserted into the stop ring 21, from the crimping part side 212 to
the stepwisely narrowing part 214, and the required safety length
to the shaping edge operation such as the connection of the ferrule
can be secured. Simultaneously, with the stepwisely narrowing part
214, it can be realized that the hole diameter is reduced and,
thus, at the tip end thereof, the ferrule side part 213 can be
fitted with the conventional spring 24, the plug frame 25 and the
like. Therefore, the conventional springs, plug frames and the like
can be employed in various embodiments, almost without any change
in their designs. It is preferable that the hole diameter 212d of
the crimping part side 212 in the present embodiment is provided so
as to have a size larger than the outer diameter 1d of the optical
fiber cord 1 by the thickness of the exposed tension member, since
the optical fiber or the tension member are exposed to fitted with
the optical fiber cord 1. Preferably, the hold diameter is about
0.1 mm to about 1 mm larger than the outer diameter of the optical
fiber cord 1, more preferably, about 0.1 mm to about 0.5 mm larger.
Further, the hole diameter 212d of at the crimping part side 212
may be partially formed, for example, into a projection shape to
the inner surface of the through hole 211. In this manner, the
exposing tension member 13 gives static friction force to the stop
ring 21 through the hole diameter 212d at the crimping part side
212 to prevent the stop ring 21 from unnecessarily moving even
though the direction of the optical fiber cord 1 during the
operation of shaping the edge, thereby obtaining the effect to
improve the assembling workability.
[0069] The total length of the stop ring 21 of an embodiment can
range from about 15 mm to about 35 mm, and preferably, in the range
from about 20 mm to about 30 mm. Within the range, assembling the
connector is possible and unnecessary length of the connector can
be controlled.
[0070] In the stop ring 21 according to an embodiment, the distance
212L between the end surface of the crimping part side 212 and the
stepwisely narrowing part 214 is preferably in the range from about
10 mm to about 30 mm, more preferably, in the range from about 15
mm to about 25 mm. Within the range, the advantage that necessary
optical fiber length to fix the ferrule can be secured can be
provided. In this case, the distance of the stepwisely narrowing
part 214 is defined based on position where the narrowing begins as
a datum point, which is similarly applied to the distance 213L
between the end surface of the ferrule side part 213 and the
stepwisely narrowing part 214, being described below (see, FIG.
3).
[0071] In another embodiment, the end surface of the distance 213L
between the ferrule side part 213 and the stepwisely narrowing part
214 is preferably within the range from about 3.7 mm to about 15
mm, more preferably, within the range from about 5 mm to about 10
mm in the stop ring 21 of the present embodiment. With such a
configuration above, it is advantageous to secure the thickness of
the seating surface for holding the spring within the stop
ring.
[0072] In yet another embodiment, when the distance 213L between
the ferrule side part 213 and the stepwisely narrowing part 214 is
1, the distance between the end surface of the crimping part side
212 and the stepwisely narrowing part 214 is preferably within the
range from about 0.5 to about 4.0, more preferably, within the
range from about 2.0 to about 3.5 in the stop ring 21 of the
present embodiment. With such a configuration, it is advantageous
to avoid the connector being suffered from excessive moment when
the optical fiber cord is bent.
[0073] FIG. 4 shows a plan view (FIG. 4(A)), and a cross sectional
view (FIG. 4(B)) of an embodiment of the crimping ring 22. The
crimping ring 22 is for crimping each of the stop ring 21 and the
optical fiber cord 1. The crimping ring 22 is configured to have a
hollow by forming the through hole 221 therein, in which the inner
diameter of the through hole is preferred, but not limited, to be
larger than the outer diameter of the stop ring 21, because it is
necessary to cover and crimp the crimping part of the stop ring 21.
Provided that, it is useful to configure the crimping ring 22 so as
to have the through hole having the diameter at the side of the
stop ring which is different from the diameter at the opposite
side, since the crimping ring 22 is also required to crimp the
optical fiber cord 1 at the other side. It is preferred that the
length of the crimping ring 22 is in the range from about 5 mm to
about 20 mm, more preferably, in the range from about 5 mm to about
15 mm.
[0074] FIG. 5 shows a plan view (FIG. 5(A)), and a cross sectional
view (FIG. 5(B)) of the ferrule 23 of an embodiment. As shown in
this figure, the ferrule 23 is disposed to the tip end part of the
optical fiber 15 in the optical fiber cord 1, and configured to
have a flange part 231 and a cylindrical part 232. To every one of
the flange part 231 and the cylindrical part 232, a through hole is
formed, through which the tip end of the optical fiber 15 can be
passed, and the ferrule can be fixed to that by adhering with an
adhesive and the like.
[0075] FIG. 6 shows a cross sectional view illustrating the spring
24 of an embodiment. As shown in this figure, the spring 24 is
configured to be hollow and spiral, and is disposed around the
buffered optical fiber 11 and between the ferrule 23 and the stop
ring 21, being useful for providing flexibility at the position of
the ferrule 23 and applying a pressure thereto. The inner diameter
24d of the spring 24 can be narrower than the diameter of the
optical fiber cord 1 of the illustrated embodiment. Specifically,
the inner diameter is about 3 mm because of the conventional
optical cable generally having about 3 mm.
[0076] The plug frame 25 can be engaged with the stop ring 21, in
which the flange part 231 of the ferrule 23 and the spring 24 are
disposed between the stop ring 21 and the plug frame 25.
[0077] The grip 26 can be engaged with the plug frame 25. The user
can connect the optical connector 2 to an apparatus such as an
optical module by grasping the grip 26.
[0078] In an embodiment, the boot 27 covers a part of the stop ring
21, the crimping ring 22 and a part of the optical fiber cord 1,
which can reduce the force applied to the optical fiber cord 1,
even when the optical fiber cord is bent. By the optical fiber
connector of the present embodiment, the cutting of the outer
jacket 14 of the optical fiber cord 1 is reduced or eliminated,
improving the appearance thereof, and increasing the bending
property thereof, as compared with the boots in the prior art.
Therefore, the boot in which parts for exposing the optical fiber
cord are partially formed can be easily employed. FIG. 7(A) shows a
schematic plan view and a cross sectional view illustrating the
boot in which parts for exposing the optical fiber cord are
partially formed, and FIG. 7(B) shows a schematic plan view and a
cross sectional view illustrating the boot in which no part for
exposing the optical fiber cord are partially formed.
[0079] Accordingly, in some embodiments, the optical fiber cord
with the optical connector is not required to cut up at the outer
jacket, and will become an optical fiber cord excellent in the
flexibility resistance. Since it is not necessary to cut up the
outer jacket, any invasions of foreign substances or drops of water
from the cut parts can be avoided. Furthermore, since it is not
necessary to hide cut parts, an excellent effect that the boot is
not elongated more than necessary can be provided.
[0080] Next, the method for manufacturing the optical fiber cord
with the optical connector according to an embodiment will be
explained below. FIG. 8 shows a flow chart relating to the method
for manufacturing the optical fiber cord with the optical connector
of the embodiment. As shown in this figure, the method for
manufacturing the optical fiber cord with the optical connector of
the illustrated embodiment comprises the steps of: passing the
optical fiber cord 1 through the boot and the crimping ring (S1);
exposing the tension member 13 and the optical fiber 15 from the
optical fiber cord 1 (S2); inserting the optical fiber cord 1 from
which the optical fiber 15 is exposed from the crimping side into
the stop ring 21 having a through hole formed thereto having a
stepwisely narrowing part where a diameter is gradually reduced
from the crimping part side to the ferrule side (S3); passing the
buffered optical fiber 11 through the spring 24 (S4); fixing the
optical fiber 15 to the tip end of the ferrule 23 (S5); sliding the
optical fiber cord 1 from the stop ring 21 to engage plug frame 25,
the ferrule 23 and the stop ring 21 with one another (S6); crimping
the stop ring 21 and the optical fiber cord 1 by the crimping ring
22 (S7); and engaging the plug frame 25 with the grip 26 and
attaching them with the boot 27(S8).
[0081] In one embodiment, firstly, the optical fiber cord 1 is
passed through the boot 27 and the crimping ring 22 (see, S1, FIG.
9). By previously fitting the boot 27 and the crimping ring 22,
subsequent crimping operation and attaching the boot 27 operation
can be facilitate.
[0082] In some embodiments, the step of exposing the optical fiber
15 from the optical fiber cord 1 (S2) (see, FIG. 10) is followed by
fixing to the ferrule 23. It is preferred that the exposure of the
optical fiber 15 is made in a stepwise manner: an exposed part in
which only the outer jacket 14 is removed; an exposed part in which
only the outer jacket 14 and the tension member 13 are eliminated;
an exposed part in which the outer jacket 14, the tension member 13
and the buffer member 12 are removed to expose the optical fiber
15. In this case, the length of the exposed part where only the
optical fiber 15 is exposed is preferably in the range from about 9
mm to about 15 mm, the length of the removed part of the outer
jacket 14 (the distance between the end surface of the outer jacket
14 to the tip end of the optical fiber 15) is preferably in the
range from about 25 mm to about 60 mm. The length of the exposed
tension member 13 is preferably in the range from about 5 mm to
about 20 mm. Here, in order to prevent the optical fiber 15 from
being damaged, the operation to eliminate the buffer member 12 can
be introduced between the step of inserting (S4) the buffered
optical fiber 11 into the spring 24 and the step (S5) of fixing the
ferrule 23 to the tip end of the optical fiber 15.
[0083] In some embodiments, the step of exposing the optical fiber
15 from the optical fiber cord 1 is carried out after the step of
passing the optical fiber cord 1 through the boot 27 and the
crimping ring 22 in order to provide the explanations for some
embodiments and to reduce the possibility that the optical fiber 15
are damaged as much as possible, the step of exposing the optical
fiber 15 from the optical fiber cord 1 is carried out prior to the
step of passing the optical fiber cord 1 through the boot 27 and
the crimping ring 22, as long as the exposed optical fiber 15 can
be inserted into the boot 27 and the crimping ring 22 without any
damages thereof.
[0084] In the step of inserting the optical fiber cord 1 in which
the optical fiber 15 is exposed from the crimping part side into
the stop ring 21 having the through-hole and the stepwisely
narrowing part where a diameter is gradually reduced from the
crimping part side to the ferrule side formed thereto (see S3, FIG.
11, the upper one showing a plan view and the lower showing a cross
sectional view), the outer jacket 14 of the optical fiber cord 1 is
inserted to contact with the above stepwisely narrowing part 214.
In this way, sufficient exposed portion of the optical fiber can be
secured without cutting up the outer jacket 14, as in the prior
art, and, thus, the optical fiber cord having an excellent
durability and flexibility resistance can be provided.
[0085] In some embodiments, the step of passing the buffered
optical fiber 11 through the spring 24 (see S4, FIG. 12) is carried
out prior to the step of fixing the optical fiber 15 to the tip end
of the ferrule 23 (S5). In some embodiments, the next step can be
carried out while spring 24 can be contained within a groove 215
for the spring, which is formed at the end surface side of the
ferrule side 213 of the stop ring 21. It is more useful the spring
24 and the stop ring 21 are temporarily fixed with each other by a
tape and the like, if possible. Because, in some embodiments, the
stop ring 21 can limit unnecessary movement by the static friction
acting between it and the tension member 13 exposed from the
optical fiber cord 1, as described above, the spring 24 can also be
capable of preventing the unnecessary movement during the shaping
edge operation by temporarily fixing the spring 24 and the stop
ring 21. For the temporarily fixing means, it is useful to use a
temporal fixture which can be detachable after the shaping edge
operation.
[0086] The step of fixing the ferrule 23 to the tip end of the
optical fiber 15 (S5, see FIG. 13) can be carried out by injecting
an adhesive to the through hole of the flange part 231 and the
cylindrical part 232, followed by inserting the optical fiber 15 to
cure.
[0087] The step of sliding the optical fiber cord 1 from the stop
ring 21 to engage plug frame 25, the ferrule 23 and the stop ring
21 with one another (S6, see FIG. 14: (A) showing a plan view, (B)
showing a cross sectional view, and (C) showing a plan view after
the plug frame 25 is engaged with the stop ring 21, respectively)
can be realized by previously providing a concave part and the
corresponding convex part to the plug frame 25 and the stop ring
21, respectively, to engage them each other, but not limited
thereto. In this step, the end surface of the outer jacket 14 at
the side where the buffered optical fiber 11 of the optical fiber
cord 1 may be within the through hole 211 of the stop ring 21, even
though said end surface is outside of the end surface of the
crimping part 212 of the through hole 211 of the stop ring 21, as
long as the end surface of the outer jacket 14 is in within the
through hole of the crimping ring 22 at crimping the crimping ring
22. In particular, when the end surface of the outer jacket 14 is
located near the end surface of the crimping part side 212 of the
stop ring 21 (preferably, within about 10 mm, more preferably,
within about 5 mm), there is an advantage of more strongly crimping
at crimping the stop ring 21 and the crimping ring 22, since the
tension member 13 can be easily disposed there between.
[0088] A method according to one embodiment may further include the
step of crimping the stop ring 21 and the optical fiber code 1 with
the crimping ring 22 (S7). For the crimping method, but it is not
limited to, for example, the stop ring 21 can be preferably crimped
by sandwiching the tension member 13 between the stop ring 21 and
the crimping ring 22 while applying a pressure from the around them
by using a crimping tool and the like, as shown in FIG. 15.
Moreover, for the method for crimping the optical fiber cord 1,
after positions of the outer jacket 14 and the crimping ring 22 are
adjusted, the optical fiber cord 1 can be crimped by applying a
pressure by using a crimping tool and the like. It is preferred
that the length where the stop ring 21 and the crimping ring 22 are
overlapped with each other is in the range from about 3 mm to about
15 mm, more preferably, in the range from about 3 mm to about 8
mm.
[0089] Then, in an embodiment, the grip 26 and the plug frame 25
are engaged with each other, and the boot 27 is disposed such that
the boot covers a part of the stop ring 21, the crimping ring 22,
and a part of the optical fiber cord 1, thereby completing the
optical fiber cable with the optical connector shown in FIG. 1.
[0090] Accordingly, the optical fiber cord with the optical
connector manufactured by the method for manufacturing of the
embodiment according to some embodiments, provide an optical fiber
cord with an optical connector of high flexibility resistance.
[0091] Although the embodiments have been described with a SC type
connector part, the embodiments can be adapted for any of a MU
type, a FC type, and LC type parts. Also, the embodiments can be
adapted for other optical connectors not listed herein, but having
a similar structure.
[0092] Although this invention has been disclosed in the context of
certain embodiments and examples, it will be understood by those
skilled in the art that the present invention extends beyond the
specifically disclosed embodiments to other alternative embodiments
and/or uses of the invention and obvious modifications thereof.
Thus, it is intended that the scope of the present invention herein
disclosed should not be limited by the particular disclosed
embodiments described above, but should be determined only by a
fair reading of the claims that follow.
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